According to the Genesis account of the creation of the universe, amidst the primordial state of chaos, void and darkness, God created light. God next separated the waters under the firmament from the waters above the firmament.
He then divided the land from the ocean, created plants, fish, birds and mammals, and finally made humankind. All of this took a period of six “days.” From this account, we can surmise that the process of creating the universe took some period of time represented by six days.
The process of creation recorded in the Bible bears some resemblance to the theory of the origin and formation of the universe as described by modern science. According to modern science, the universe began as expanding plasma.
Out of the chaos and void of space, the heavenly bodies formed and gave light. As the molten earth cooled, volcanic eruptions filled the sky with a firmament of water. The land rose and the water fell as rain, creating the continents and oceans.
Next, the lower plants and animals came into being. Then came fish, birds, mammals, and finally humankind, in that order. The age of the Earth is calculated to be several billion years. Considering that the account of the creation of the universe recorded in the Bible thousands of years ago nearly coincides with the findings of modern scientific research, we are reassured that this biblical record must be a revelation from God.
The universe did not suddenly spring forth complete, without regard to the flow of time. In fact, its origin and development took an enormous length of time.
Therefore, the biblical period of six days for the completion of the universe is not to be reckoned by the number of literal sunrises and sunsets. It symbolizes six ordered periods of time in the creation process.
Sun Myung Moon